In a general-purpose internal combustion engine used as a drive source to be used for a generator, an agricultural machine or the like, an internal combustion engine using an automatic choke device is proposed to improve a starting performance in cold start operation. Such automatic choke device controls opening and closing of a choke valve in a carburetor by an actuator when starting the internal combustion engine so as to produce a higher concentration of fuel mixed in the air (hereinafter called as air-fuel ratio) and improve the starting performance of the internal combustion engine.
Such technique is proposed in Japanese Laid-Open Patent Application No. 2007-23838 (Patent Literature 1).